World Trade Center

SUmmary

Silverstein Properties had signed a lease on the World Trade Center complex only six weeks prior to the buildings collapse as a result of the terrorist attacks on September 11th. Twenty-four separate insurance companies combined to provide $3.5 billion in property insurance per occurrence. Silverstein Properties believed that the attacks were two separate occurrences and they were entitled to approximately $7 billion of coverage. Z-Axis was part of the Silverstein forensic team along with engineers from Weidlinger Associates, Hughes Associates, and LZA Thorton/Tomasetti.

This team of experts was compiled to analyze what was essentially one of the biggest crime scenes in history. Z-Axis was asked to triangulate the speed and angle of the impacts by analyzing video evidence of the event. Based on these calculations, the team created simulations, animations, interactive presentations, and other supporting evidence depicting the impact and resulting collapse of the towers.

One such exhibit created by Z-Axis was a scientifically accurate 3-dimensional animation of the impacts and subsequent collapse of each tower. Models of the airplanes, towers, and surrounding structures were created using data output from Weidlinger’s FLEX and SAP 2000 simulators. The impact models depicted over 800,000 elements in every frame, while the collapse sequences contained over 5 million elements per frame. The computer-generated models included details of all the elements of construction, including the towers’ cores, exterior tubes, floors, hat truss systems and fireproofing. The exhibits transformed the experts’ raw data into illustrations of the strength of every column and beam in the towers, both before and after the airplane impacts and subsequent fires. The modeling and animation were so accurate that when overlaid on actual videos taken on 9/11, the motion was virtually identical. In addition to the trial, the Z–Axis animations have been used outside of the courtroom in various documentaries on PBS and the Discovery Channel regarding 9/11, and have also been shared with the National Institute of Standards (NIST) and other industry groups to help them understand the events of 9/11 and plan future construction standards.

The total amount underwritten by the combined insurance companies was $3.5 billion. A previous trial had concluded that the portion of insurers that had underwritten $2.4 billion of the policy were liable for only one occurrence based on their version of the policy. A second trial presented by the team including Z-Axis, determined whether the attacks constituted two separate occurrences for the nine remaining insurance companies and remaining $1.1 billion in coverage. Z-Axis exhibits and animations were used to illustrate the events of 9/11 with a winning outcome for the expert team and its client at trial. The verdict determined that it was indeed two occurrences for insurance claims purposes, increasing the total amount of coverage provided by these nine companies from $1.1 billion to $2.2 billion.